Extremely high concentration of mexotrexate in blood serum leading to development of acute renal failure in a patient with acute lymphoblastic leukemia after high-dose consolidation

Acute renal failure (ARF) is one of rare and severe methotrexate(MT)-induced complications in patients with acute lymphoblastic leukemia. A case of MT-induced renal dysfunction with an extremely high serum MT concentration is reported. This toxicity required conduction of hemodiafiltration for extracorporeal MT elimination. The presence of homozygous mutation of methylene-tetrahydrofolate reductase reflects an individual metabolism of MT and its renal clearance.